What does Matthew 27:63 mean?
Some of the chief priests and Pharisees have come to see Pilate on Saturday, the Sabbath day. From their perspective, they have succeeded in protecting themselves and the people from a false Messiah (John 11:48–53). They were able to illicitly convict Jesus of blasphemy (Matthew 26:57–68), condemned to death, and crucified by the Romans (Matthew 27:24). Some of them likely saw Him die with their own eyes (Matthew 27:39–43).As religious leaders, however, these men understand the power of symbols. They want to be sure that not only is Jesus dead, but that everything He stood for is clearly refuted. That includes avoiding any possible deceptions or changes to the claims made about Jesus. They remind the Roman governor that Jesus said He would rise from the dead after three days (John 2:19–22). They do not believe, of course, that this will happen. They are worried that someone will steal the corpse and try to make it look like it has happened.
That possibility, it seems, is enough to convince Pontius Pilate to seal and guard the tomb, for a brief time (Matthew 27:64–66).